#include <bits/stdc++.h>

using namespace std;


int main() {
    string s;
    cin >> s;

    string t = "yukicoder";
    for (int i = 0; i < s.length(); ++i) {
        if (s[i] == '?') {
            cout << t[i] << endl;
            return 0;
        }
    }
}